FOCAL MECHANISM DETERMINATION OF EARTHQUAKES IN “KS” GEOTHERMAL FIELD IN JUNE 2010 – SEPTEMBER 2011 PERIOD BY MOMENT TENSOR INVERSION

• Main Author: SURYAWIRAWAN NIM : 12313036, KARTYAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22764
• Institution: Institut Teknologi Bandung

“KS” geothermal field is a geothermal field that has been operated. In an exploitated geothermal area, there are several cause for a microearthquakes, such as fluid injection into the reservoir, underground fluid migration, drilling activity, as well as fault movement. In addition, it’s possible for microearthquakes in a <br /> <br /> <br /> geothermal field to have a Double Couple or a non-Double Couple mechanism. In “KS” geothermal field, earthquake events are recorded by seven three-components seismometer station situated around the field. In this research, data processing for identification of focal mechanism has been done for 29 earthquake data in the <br /> <br /> <br /> period of June 2010 – September 2011. Focal mechanism determination is done with moment tensor inversion method by ISOLA software. According to the result, <br /> <br /> <br /> 5 faults have been identified, of which four are strike slip fault and one is a normal fault. From this result it is concluded that the earthquakes in “KS” geothermal field is influenced by faults movement which is caused by gravity and regional stress. Other than that, it can also be said that the process of fluid injection and extraction also plays a role in generating earthquakes in “KS” geothermal field.